Preclinical Efficacy of Peripheral Nerve Regeneration by Schwann Cell-like Cells Differentiated from Human Tonsil-Derived Mesenchymal Stem Cells in C22 Mice

Application of Mesenchymal Stem Cell-Derived Schwann Cell-like Cells Spared Neuromuscular Junctions and Enhanced Functional Recovery After Peripheral Nerve Injury

In general, the nerve cells of the peripheral nervous system regenerate normally within a certain period after the physical damage of their axon. However, when peripheral nerves are transected by trauma or tissue extraction for cancer treatment, spontaneous nerve regeneration cannot occur. Therefore, it is necessary to perform microsurgery to connect the transected nerve directly or insert a nerve conduit to connect it. In this study, we applied human tonsillar mesenchymal stem cell (TMSC)-derived Schwann cell-like cells (TMSC-SCs) to facilitate nerve regeneration and prevent muscle atrophy after neurorrhaphy. The TMSC-SCs were manufactured in a good manufacturing practice facility and termed neuronal regeneration-promoting cells (NRPCs). A rat model of peripheral nerve injury (PNI) was generated and a mixture of NRPCs and fibrin glue was transplanted into the injured nerve after neurorrhaphy. The application of NRPCs and fibrin glue led to the efficient induction of sciatic nerve regeneration, with the sparing of gastrocnemius muscles and neuromuscular junctions. This sparing effect of NRPCs toward neuromuscular junctions might prevent muscle atrophy after neurorrhaphy. These results suggest that a mixture of NRPCs and fibrin glue may be a therapeutic candidate to enable peripheral nerve and muscle regeneration in the context of neurorrhaphy in patients with PNI.

A Review and Bibliometric Analysis of Studies on Advances in Peripheral Nerve Regeneration

Peripheral nerve injuries (PNIs) pose significant clinical challenges due to their complex healing processes and the often incomplete functional recovery. This review and bibliometric analysis aimed to provide a comprehensive overview of advancements in peripheral nerve regeneration research, focusing on trends, influential studies, and emerging areas. By analyzing 2921 publications from the Web of Science Core Collection, key themes such as nerve regeneration, repair, and the critical role of Schwann cells were identified. The study highlights a notable increase in research output since the early 2000s, with China and the United States leading in publication volume and citations. The analysis also underscores the importance of collaborative networks, which are driving innovation in this field. Despite significant progress, the challenge of achieving complete functional recovery from PNIs persists, emphasizing the need for continued research into novel therapeutic strategies. This review synthesizes current knowledge on the mechanisms of nerve regeneration, including the roles of cellular and molecular processes, neurotrophic factors, and emerging therapeutic approaches such as gene therapy and stem cell applications. Additionally, the study revealed the use of nanotechnology, biomaterials, and advanced imaging techniques, which hold promise for improving the outcomes of nerve repair. This bibliometric analysis not only maps the landscape of peripheral nerve regeneration research but also identifies opportunities for future investigation. This study has some limitations, including reliance on the Web of Science Core Collection, which may exclude relevant research from other databases. The analysis is predominantly English-based, potentially overlooking significant non-English studies. Citation trends might be influenced by shifting research priorities and accessibility issues, affecting the visibility of older work. Additionally, geographical disparities and limited collaboration networks may restrict the global applicability and knowledge exchange in this field.

Adipose Tissue Derivatives in Peripheral Nerve Regeneration after Transection: A Systematic Review

INTRODUCTION

Peripheral nerve injury (PNI) is increasingly prevalent and challenging to treat despite advances in microsurgical techniques. In this context, adipose tissue derivatives, such as adipose-derived stem cells, nanofat, and stromal vascular fraction have been gaining attention as potential allies in peripheral nerve regeneration.

OBJECTIVES

This study aims to explore the use of adipose tissue derivatives in nerve regeneration following peripheral nerve transection in murine models. Thus, we assess and synthesize the key techniques and methods used for evaluating the obtained nerve regeneration to guide future experimental research and clinical interventions.

METHODOLOGY

A systematic review was conducted in February 2024, adhering to the Cochrane and PRISMA 2020 guidelines, using the PubMed, SciELO, and LILACS databases. The focus was on experimental studies involving adipose tissue derivatives in nerve regeneration in animal models post-transection. Only experimental trials reporting nerve regeneration outcomes were included; studies lacking a comparator group or evaluation methods were excluded.

RESULTS

Out of 273 studies initially identified from MEDLINE, 19 were selected for detailed analysis. The average study included 32.5 subjects, with about 10.2 subjects per intervention subgroup. The predominant model was the sciatic nerve injury with a 10 mm gap. The most common intervention involved unprocessed adipose-derived stem cells, utilized in 14 articles.

CONCLUSIONS

This review underscores the significant potential of current methodologies in peripheral nerve regeneration, particularly highlighting the use of murine models and thorough evaluation techniques.

Therapeutic Effect of Schwann Cell-Like Cells Differentiated from Human Tonsil-Derived Mesenchymal Stem Cells on Diabetic Neuropathy in db/db Mice

BACKGROUND

Diabetic neuropathy (DN) is the most common complication of diabetes, and approximately 50% of patients with this disease suffer from peripheral neuropathy. Nerve fiber loss in DN occurs due to myelin defects and is characterized by symptoms of impaired nerve function. Schwann cells (SCs) are the main support cells of the peripheral nervous system and play important roles in several pathways contributing to the pathogenesis and development of DN. We previously reported that human tonsil-derived mesenchymal stem cells differentiated into SCs (TMSC-SCs), named neuronal regeneration-promoting cells (NRPCs), which cells promoted nerve regeneration in animal models with peripheral nerve injury or hereditary peripheral neuropathy.

METHODS

In this study, NRPCs were injected into the thigh muscles of BKS-db/db mice, a commonly used type 2 diabetes model, and monitored for 26 weeks. Von Frey test, sensory nerve conduction study, and staining of sural nerve, hind foot pad, dorsal root ganglia (DRG) were performed after NRPCs treatment.

RESULTS

Von Frey test results showed that the NRPC treatment group (NRPC group) showed faster responses to less force than the vehicle group. Additionally, remyelination of sural nerve fibers also increased in the NRPC group. After NRPCs treatment, an improvement in response to external stimuli and pain sensation was expected through increased expression of PGP9.5 in the sole and TRPV1 in the DRG.

CONCLUSION

The NRPCs treatment may alleviate DN through the remyelination and the recovery of sensory neurons, could provide a better life for patients suffering from complications of this disease.